C# Deployement

Question

Hi,
I am new to C# and i have creatred one setup file using VS2005, that is successfully created and i was install  that setup file and that setup file  is  install succcessfully. but my system all exe file and OS exe file are changing defferent format (i.e is windows cannot open this files).how to i have restore my all system exe file. can anyone give an idea.
i have done this way:
I have  developed one setup file in the setup file  File Type (setup)--> properties--> extensions-->.exe.
and
File Type(setup)--> properies-->command--> Notpad.exe
Thanks,
kiran
 
 
Thanks.
kiran.